Goods such as medical supplies, blood, and vaccines are extremely temperature sensitive and need to be maintained within a given temperature range to prevent deterioration, denaturing and spoilage. Thermal control is particularly challenging during transport of such thermally labile goods.
Shipment of such thermally labile goods is commonly effected with both actively controlled (i.e., powered) and passively controlled (i.e., unpowered with thermally conditions phase change panels) thermally insulated shipping containers. Vacuum insulated panels (VIPs) are the generally preferred form of thermal insulation in such shipping container as they provide superior thermal insulation, so long as the internal vacuum remains intact. However, once the vacuum is lost the thermal performance of a VIP is greatly reduced.
While generally preferred, VIPs present a couple of challenges. First, it is difficult to secure VIPs into place within a thermally insulated shipping container as the vacuum sealed nature of the VIPs prevents use of traditional pass-through fasteners. JP2000248653 attempts to resolve this challenge by encapsulating a VIP within rigid foam insulation, and mounting the resultant assembly with nails driven through the foam only margins of the assembly. While effective for allowing VIPs to be mounted with traditional pass-through fasteners, the foam-only margins leave large gaps between the VIPS, reducing the thermal insulating value of the assembly.
U.S. Pat. No. 8,202,599 offers another solution by providing sealed through-holes in the VIP. While effective for facilitating mounting of the VIPs with traditional fasteners, formation of the through-holes greatly increases both the cost of the VIPs and the likelihood of a premature loss of vacuum resulting from an imperfect sealing of one of the through-holes.
Another challenge presented by the use of VIPs is the limited average useful lifespan of VIPs relative to other components of a typical thermally insulated shipping container, resulting in a frequent need to replace spent VIPs and/or refurbish thermally insulated shipping containers with a fresh set of VIPs. Hence, it is desired to thermally insulate shipping containers with VIPs in such a manner that the VIPs can be readily removed and replaced. Current efforts to facilitate replacement of VIPs in thermally insulated shipping container are complex and expensive, and/or result in gaps between the VIPs, reducing the thermal insulating value of the VIPs.
Accordingly, a need continues to exist for an inexpensive VIP assembly that allows for both a complete unbroken lining of a thermally insulated shipping container with VIPs, and quick and easy attachment and detachment of the VIPs to the thermally insulated shipping container.